Pantograph



Oct. 26, 1-926. 1,604,883

. c. DEVE PANTOGRAPH Filed March 5, 1925 Patented 26, lent l.

earner CHARLES Drive, or PARIS, FRANCE.

PANTOGRAPH.

Application filed March The present invention appertains to improvementsin reproducing or pantographic apparatus, and it has for its object toprovide means which will permit of reproduction on any surface of anygiven pattern and on a reduced scale, this without distortion ordeformation perceptible to the naked eye, and conversely, thereproduction of the pattern with amplification or enlargement when suchis desired.

A further object in view is to provide such a construction of devicethat it may be employed to distort the original pattern in any givenmanner; for example, by changing straight lines of the pattern sketchinto curved lines, with enlargement or reduction in size as desired.

One of the novel characteristics of the pantographic device forming thesubject matter of this invention resides in the elimination of joints,making it easy to operate and to assemble, as well as to adjust. whilethe work produced by the same will involve the highest precision. Theapparatus is very compact and simple as compared with apparatus capableof producing corresponding work.

In the illustration depicted in the drawing I have disclosed theapparatus as arranged to reproduce a pattern upon a piece of glass, butit will be obvious to those skilled in the art to which the inventionrelates that the reproduction operation applies equally well to otherpurposes or objects.

7 In the drawing:

Figure 1 is aside eleyation of the pantographic device with the work andpattern support with which it cooperates shown in section;

Figure 2 is a fragmentary plan view of the beam of the pantographicdevice showing more clearly the pin and slot connection employed in thisapparatus.

On the main frame. B I provide a work support which may be of any of thewell known types of holders for sustaining the object on which theengraving or reproduction is to be transposed, the work surfacehereinafter referred to being designated V. Adjacent this work surfaceis disposed a pin or post P which constitutes a pivot mounting for thebeam 1 of the pantographic device. This postmay be fixedly secured tothe support B so as to project perpendicularly there-- from or it may bemounted for adjustment on support with relation to war 5, 1925, SerialNo. 13,255, and in France May 17, 1924.

surface, as shown in the drawings, and this post may also be inclinedwith relation to the work s face, depending upon whether an inclinationis desired, as for instance when a distortion of the pattern is to beproduced.

Under some conditions it may even be necessary to give to the post P acertain degree of curvature, and these modifications are clearly withinthe purview of this invention.

The adjustment of the post with relation to the work surface V obviouslycontrols the degree of reduction or enlargement and it may be arrangedto cooperate with a movable scale, not shown, so as to permit rapid andaccurate variations in the degree of reduction desired.

The beam 1 is slotted at its lower end as indicated a-t2 to receive thepost or pivot P so as to permit relative swinging and sliding movementsof the beam in the operation of this device. It will be understood thatthis mounting may readily be reversed by providing the beam 1 with afixed pivot member havinga sliding connection with the frame B. so thatI do not wish tobe limited to the specific form of connection which isdepicted in the drawings so long as the freedom of movement referred tois obtained.

The beam 1 has mounted thereon a holder 4 adj ustably secured by meansof the clamplng ew 5 and carrying at its extremity the engravinginstrumentality 3 which in the instant case is a diamond. I desire it tobe further understood that the character of tool which is mounted in thebeam depends upon the nature of work which is to be done or thecharacter of the material on which the scribing is to be effected. Itmay possibly be replaced by a Stanh-ope lens, a well known article, ashereinafter referred to. especially where reproduction of microscopicaldrawings or patterns is involved. Such a device essentially consists ofa magnifying lens the contacting surface of which is provided with amarker by means of which to follow the pattern, and it is consideredunnecessary to illustrate or further describe this feature of theapparatus in view of its well known characteristics. a, I

At the upper end, the beam is provided with a tracer arm 6 whichprojects at right angles and is provided adjacent its outer extremitywith a tracing point 7 and a pencil holder or socket 3.5 to n; a mark. H

vpoint 3 on the surface V is disposed.

strument or pencil C. The arm 6 is capable of adjustment on the beam 1so as to vary the -distance of this arm with reference to the scribingor engraving tool 3 whereby this may be brought closer together orseparated, as the case may require.

The tracer rests upon and operates over the surface of the support 8 onwhich the drawing to be reproduced by the engraving It is to beparticularly noted that the pattern support or surface is angularlyrelated to the work surface V, this marking the essential departure fromthe usual arrangement in well known apparatus in which the two surfacesare generally disposed in parallel relationship to each other and to theplane of travel of the instrument.

It will be obvious that during the engraving by the point 3 the pencil Cwill make a faithful reproduction on the pattern surface of the designwhich is cut into the surface V, thus providing a duplicate of exactlywhat is engraved on the work surface. If the duplicate is not needed thepencil C may be displaced at will.

The tracer 7 may be arranged to cooperate with or slide in the groovesof. a vignette or a sheet of metal having a design cut thereinto andwhich may be placed upon the pattern support; these vignettes may be,for instance, trademarks, stamps, names 0 firms, etc.

It will be obvious that the extent of pressure of the engraving pointupon the work surface will vary according to the degree of inclinationof the beam 1 and it is therefore easy to regulate this pressure bygiving the proper inclination to the frame B on which the post P and thepattern support 8 are ahixed. A movable counterweight 9 is attached tothe lower or slotted end of the beam 1 and materially assists in theregulation of the pressure which is produced.

While the post P is of a size which will permit quite free movement ofthe beam in the operation of the device, any desired means, may beemployed to eliminate side play whether this be by way of the provisionof a weight or of a spring so arranged as tomaintain the contact of thebeam against the post on the same side all times In the apparatus hereindisclosed it will be apparent that the movements of the arm 6 around thepivot or post P will be reduced in the ratio of the respective distancesof the scriber 3 and the tracer 7 to the post or pivot P. In addition,the movements of the tracer in the plane of the beam 1, are reduced bythe engraving point 8, but the degree of reduction obtained depends uponthe angle between the lines formed by the intersection of the verticalplane passing through the points 3 and 7 with the respective pattern andwork surfaces, together with the progress of the tracer? in the crossplane. For example, one can give this angle a value such that the degreeof reduction will be the same for the two movements.

It is easy to see that under these conditions the sketches or drawingsobtained will not be similar but will be homographic. The patternsurface 8 may be such a manner that this homographic will be as near tocorrespondence with the pattern as possible. The theoretical shape whichis to be given to the pattern surface 8 may be mathematicallycalculated; generally it is curved in two different directions but forpractical purposes it is possible to use a spherical surface the centerof which is in the neighborhood of the pivot.

One can also, through a judicious choice of the perameters of theinstrument (table surface, shape and position of the pivot)systematically distort the original drawing. Thus, by choosing for thesurface of the pattern support a proper degree of curva ture,coaxialwith the said pivot bases, characters inscribed on the parallellines of the support will be engraved according to circumferencesconcentric with the pivot, and with a rate of reduction which increaseswhen nearing the center. This arrangement is particularly suited forengraving on coins, metals or glass for Opticians, in which case, theobject to be engraved is centered below the pivot.

One can. see that the engraving point 3 can be made to follow a sketch,traced beforehand on the surface V, and in this case the pencil point inthe socket 10, or the tracer 7 constitutes the scriber, reproducing thissketch on the support 8 with amplification. In other words, for the purposes of this description it is immaterial whether the part 3 isconsidered the engraving point or the tracer, or whether the arm (3 is ascribing arm or tracer, the functions of these parts beinginterchangeable dependent upon whether the work to be done involvesenlargement or reduction.

With this understanding it will be apparent that the instrument may beused. to reproduce microscopic drawings executed on the surface V whichare to be reproduced on other similar surfaces by the double oper ationof first amplification or enlargment and then reduction, after thefollowing manner: Assuming that the drawing which is to be reproduced ison the surface V. I substitute, as hereinbefore premised, a Stanhopelens for the engraving point 3, this lens having a slightly convexbearing surface provided with astandard or mark. The said mark is placedon the design and the latter is followed by moving the arm 6: the pencilG or, as faras that is concerned,

arranged in lift) an index which may be aflixed to the arm 6, willreproduce homographically on the surface 8 the design on V. Substitutingfor the surface V, the surfaces or surface that is now to be engraved,and replacing the diamond 3 in its proper place, the tracer followingthe reproduction ust made on the surface 8 will reproduce on the saidsurface V the homographic sketch and this sketch will be a strictreproduction of the original design which was on said surface. In likemanner of substitution, the engraving point 3 may be replaced by arotating or routing tool operated in any desired manner by a flexibledriving element as is well known to those skilled in the art to whichthis invention relates. The depth of the engraving may be readilycontrolled. If it is to be uniform a simple stop piece (not shown) maybe applied to the beam which will limit the depth of the cutting action.If the depth of the engraving must vary, as in the case of engravingcameos, metal stamps, etc., then a special arrangement must be provided.

The surface 8 may be of cylindrical or conical form if the sketch ordrawing to be obtained is large, or if an extensive enlarge ment isdesired it may be movable. It may be made up as follows: around a largecylindrical tube may be placed the paper bearing the sketch and the worksurface V would likewise be placed upon a similar cylindrical surface,the size of which must be in proportion to the reduction desired. Toobtain an enlargement of a microscopical sketch one may use as a worksurface a cylinder the generatrices of which are inclined wiht respectto the pivot at an angle corresponding to the degree of amplificationdesired.

It is to be understood that the device may be constructed so that thepivot P will lie between the points 3 and 7. l/Vith such a constructionthere may be an interference in the reproducing although suchinterference may not amount to an inconvenience when reproducing onglass, because of its transparency. In any event, to prevent thisinterference it is only necessary to give to the surface 8 a symmetricalincline, i. e. a curvature the center of which would lie above thesurface V, in a position symmetrical with that which it has on theaccompanying drawing. which produces an inversion in the longitudinaldirection as well as an inversion transversely. This arrangement isrecommended where the instrument is to be affixed on a machine forengraving grad uated scales and for inscribing numerals, degree marks orthe like associated therewith.

The instrument may be placed in front of the piece of work upon whichthe said scale is to be engraved, the said piece being movable or it mayalso be mounted upon the slide or carriage of the scale engravingmachine, the object to be marked with divisions remaining still; inbothcases, one places thereon a small shoulder which is exactlyrectilinear and is situated in the vertical plane of the said pivotpost; the slide 7 bears againstthis shoulder to trace a line of thegraduated scale; with this in view, one can carve a straight groove inthe table; the scale numbers may be engraved at the same time; forexample, before tracing the divisions, one may write above them thefigures indicating the tens, (or the figure for the degrees in the caseof angles) then after having traced the line of the division itself, onecan write before the figure representing the units, or the decimals; thefigures and lines indicating the divisions can thus be en graved at thesame time by means of a continuous line so that the figures arematerially attached to the corresponding line thus eliminating allerrors when reading them.

As guidance in the engraving of figures, the operator can see under thelateral index on arm 6, and at the proper place, the guidefigure whichhe has but to follow to engrave the correct number; these guide figuresare printed or engraved on two vignette disks,

one bearing the figures of the tens and the other the figures of theunits; by a mechanism easy to build up and which varies according to themodel of the dividing machine, these disks revolve when the carriage ofthe machine moves; for a movement of the carriage of one millimeter, forexample, the vignette disk of the tens (or degrees) advances or turnsback, one unit, whereas for movements of 0.2 mm. the units disk advancesby two units (tenths of millimeters). One may therefore engrave at leastten figures side by side on a space of one millimeter and trace severalhundreds of strokes or divisions in the space covered by one millimeter.

When the diamond point engraves working upwards, it engraves more deeplythan when it works downhill; therefore, if one brings the piece V nearerto vertical, the engraved strokes obtained in making the slider 7 slideupwards on the table will be heavier than if the slider slides downward.Bearing this in mind, it is therefore possible to have divisions shownin very light engraving and have the figures corresponding showing lightand heavy strokes, the heavy strokes being heavier than the divisionmarks, which gives a very attractive appearance for the numbering.

Having thus described my invention, what I claim as new is l. inreproducing apparatus of the class described, the combination of a framecom prising a attern support and a work support angu arly related to thepattern sup ill) port, a pantographic device including abeam having afree swinging and sliding connection with the frame at one end, a tracerarm fixed to the beam to cooperate with the pat tern support, and ascribing member mounted on said beam in position to coact with the worksupport, the transformation of each point of the pattern in a transversedirection depending upon the ratio of the distances from the tracer armand scribing: member to the connection to the frame, and thetransformation of each point of the pattern in a longitudinal directiondepending upon the inclination in the surface of the pattern support tothe work surface at the particular point. 7

2. In reproducing apparatus of the class described, the combination witha pattern support having a convex surface and a work support, thesurface of which is disposed at an angle to the convex surface, apantographic device composed of a tracer coacting with the convexsurface and a scriber coacting with the work surface, and means establishing a relation between said device and one of said surfaces andpermitting free lateral and longitudinal movements of the tracer andscriber with relation to their re sp'ective cooperative surfaces.

3. In reproducing apparatus of the class described, the combination witha pattern support having a convex surface and a work neoases support thesurface of which is disposed at an angle to the convex surface, apantographic device composed of a tracer coacting with the convexsurface and a scriber coacting with the work surface, and pin and slotconnection between the device and the frame permitting free swinging andlongitudinal movements of the device.

l. in reproducing apparatus of the class described, the combination withangularly related pattern and work surfaces of a pantographic devicecomposed of a beam, a pivot member coacting with said beam and withrespect to which it has sliding pivotal movement, a tracer arm adjustably mounted on said beam, and a scriber carried by said beam andoperated through the instrumentality of said beam and tracer.

In reproducing apparatus of the class described, the combination of aframe or support, a work support thereon, a pattern support thereon andangularly related to said work support and having a convex surface, apost adjustably mounted on said frame, a beam mounted on said post tohave pivotal sliding: movement with relation thereto, and reproducing:means on said beam coacting with the respective work and patternsurfaces.

In testimony whereof I affix my signature.

CHAR-LES DEVE.

